Preheat the oven to 350 degrees. To make the stuffing, sauté the chopped onions slowly in the vegetable oil until they soften but don't brown. Add the matzo meal, apples, parsley, salt and pepper. Mix well. Add 1/4 cup water, or more as necessary to bind the stuffing, and let the mixture cool. Just before cooking, cut a pocket in the veal and fill with the stuffing; skewer the opening closed.

Scatter the sliced onions, garlic and carrots in a large roasting pan. Place the veal on top and rub with salt and pepper. Add enough water to the pan to cover the vegetables but not the veal. Cover the pan with aluminum foil and roast for 2 hours. Remove the foil and cook another 45 minutes, or until the top is crisp and brown and the meat is cooked until pink is gone. Remove the breast to a cutting board. With a slotted spoon, remove the vegetables and skim as much fat as possible from the cooking liquid. Return the vegetables to the liquid, and place pan over high heat, scraping to loosen bits stuck to the bottom.